PLEASE HELP - JMK PCBs Super Phaser (no signal coming through)

[jfrabat]

OK, more progress...  but not yet there!

First, I figured since I did not have the short before I replaced the socket, it was likely there was some sort of solder bridge between the socket and the board.  So I decided to remove and re-install the socket, and the short circuit went away.  While at it, I replaced all the wiring, as from all the moving around, they were becoming frail at the solder joint.  Pots are also a bit frail from all the bending, but those I left in for now.

Once again, sound is coming out of the board, so that is the progress part.  The downside is that (1) I am getting clipping (unless I turn the trimpot all the way), and even then, I am not getting any phasing.

Here is what I mean:

It is a bit noise, as it is raining (the amp is RIGHT next to the balcony door, so you can hear the water from the rook hit the balcony floor) and my kids are on the TV, but this should get you an idea of what I mean.  By the way, I am just strumming the strings of the guitar, which is hanging in the rack!

Here are the voltages as of today (all puts ~12 o'clock, including trimpot):

Q1:
G: 4.93V
S: 4.15V
D: 2.16V

Q2:
G: 4.15V
S: 4.15V
D: 2.17V

Q3:
G: 4.15V
S: 4.15V
D: 2.17V

Q4:
G: 4.52V
S: 4.15V
D: 2.17V

Q5:
E: 2.26V
B: 3.65V
C: 4.15V

IC1
1: 4.12V
2: 4.12V
3: 3.96V
4: 0V
5: 4.11V
6: 2.15V
7: 4.15V
8: 8.5V

IC2
1: 4.18V
2: 4.15V
3: 4.15V
4: 8.48V
5: 4.15V
6: 4.14V
7: 3.95V
8: 5.05V
9: 4.69V
10: 4.51V
11: 0V
12: 4.83V
13: 5.56V
14: 4.53V

Speed:
1: 2.22V
2: 2.19V
3: 4.09V

Width:
1: 2.27V
2: 2.19V
3: 2.19V

Bias:
1: 0V
2: 2.27V
3: 4.15V

Vref: 5.72V

This is frustrating...  It does not work, then it sends sound through, but no phasing, then no sound but oscillation in the FETs, then sound coming through, but no oscillation... 

[Slowpoke101]

Slowly getting there. Voltages look better, much better.
Adjusting for phasing can be tedious - actually it is very tedious. You may need to secure the board so it doesn't move around you work bench.
Set both rate and width to maximum. Set the bias trim-pot fully clockwise.
Gently strum your guitar and slowly turn the bias trim-pot anti-clockwise.
At some point you should notice some phasing.

Remember, adjust the bias slowly. It is very easy to miss the phasing point.

[jfrabat]

What about the clipping?  That is part of the adjustment process?

[Slowpoke101]

Clipping is not a wanted effect (with this phaser ) and can make it difficult to hear the phasing point.
Try to reduce your input signal level (turn the guitar volume down a bit...or strum more softly ).

This phaser is based on the MXR Phase 90 which doesn't usually add distortion to the output signal.
It will if you over-drive the input and it will sound really bad.

[jfrabat]

Clipping is not a wanted effect (with this phaser ) and can make it difficult to hear the phasing point.
Try to reduce your input signal level (turn the guitar volume down a bit...or strum more softly ).

This phaser is based on the MXR Phase 90 which doesn't usually add distortion to the output signal.
It will if you over-drive the input and it will sound really bad.

I think I found one of the issues...  The SPEED pot had broken from all the troubleshooting, so I replaced it.  Legs 2 and 3 were broken and made intermittent contact.

Anyway, I set the board in a board holder I had (never actually used it, but have had it for YEARS!), and hooked it up.  It is SOMEWHAT working.  3 things I need to figure out, though:

1. Need to adjust it (and this being my first phaser, how to do it; I am looking for the Phaser 90 sound)
2. I get some intermittent  distorted sound at higher speed settings.   I get some really odd sounds at full speed!  Probably related to the last point, but I thought I would point this out.
3. I still cannot get that phasing sound (last time I checked voltages, I had no oscillation in Q1~4; will check again, though).

[jfrabat]

Just checked Q3 (easiest to reach right now), and oscillation at the Gate is 2.06V to 2.14V, so it is oscillating

[Slowpoke101]

Well it seems that you are nearly there. OK on the voltages on Q3's Gate but I do think that it may be a bit low but further adjustment of bias will help.
Set the Speed (rate ) pot to minimum and measure the voltage on pin 7 of IC1. It should vary (slowly, be patient ) between about 2 volts and 7 volts. Just make sure that it is doing so.
That horrible distortion (with increased volume ) near the start of your last video is bad. Replace IC2 and see if the distortion goes away. Unfortunately where you are getting that distortion problem is where the phasing effect should occur.

[jfrabat]

Replaced IC2 with another TL074.  Not yet tested sound, as the kids are sleeping.

I set SPEED to minimum, and voltage at pin 7 of IC1 is not oscillating.  I waited 2 minutes, and it was stuck on 4.34V.  I take it in 2 minutes, it should at least change 0.01V, right?  In order to see some sort of oscilation, I need to set speed pot to about 66~75% of full turn.  And even then, oscillation is between 2.80V and 4.23V.

[jfrabat]

The new IC2 seemed to have gotten rid of that distortion sound.  WIDTH and BIAS working as they should.  Still have the issue at max speed (clicking sound), and still getting no phasing (not sure if adjusting BIAS is what I am missing).

As far as IC1 pin 7 voltage, it slowly comes up to 4.35V, and then it just stops there.  No oscillation.  You can see it below.